Paolo Scannapieco

Computational reconstruction of the human skeletal muscle secretome

In multicellular organisms, secreted proteins play pivotal regulatory roles in intercellular communication. Proteins secreted by skeletal muscle can act locally on muscle cells through autocrine/paracrine loops and on surrounding tissues such as muscle blood vessels, or they can be released into the blood stream, thus producing systemic effects. By a computational approach, we have screened 6255 products of genes expressed in normal human skeletal muscle. Putatively secreted proteins were identified by sequential steps of sieving, through prediction of signal peptide, recognition of transmembrane regions, and analysis of protein annotation. The resulting putative skeletal muscle secretome consists of 319 proteins, including 78 still uncharacterized proteins. This is the first human skeletal muscle secretome produced by computational analysis. Knowledge of proteins secreted by skeletal muscle could stimulate development of novel treatments for different diseases, including muscle atrophy and dystrophy. In addition, better knowledge of the secretion process in skeletal muscle can be useful for future gene therapy approaches. Proteins 2006.

A second timeless gene in Drosophila shares greater sequence similarity with mammalian tim

R.C. and C.P.K. were supported by grants from the European Community and CRUI-MURST-British Council, R.C. by grants from MURST-progetti nazionali and Ministero per le Politiche Agricole, and E.R. by a David Phillips Fellowship from BBSRC.

A novel gene (PD1) with a potential role on rat spermatogenesis

PD1 is a novel protein particularly expressed at the testicular level. The relative cDNA sequences were cloned from human and rat testis libraries revealing an open reading frame for a protein of 520 and 511 amino acids respectively. The human PD1 amino acid sequence shows 85% identity with rat sequence suggesting that PD1 gene has been highly conserved during mammalian evolution. Immunohistochemical analysis showed that this protein is detected in the tubular compartment of the testis and, in particular, in the cytoplasm of the Sertoli cells. PD1 expression is not constitutive but seems to be under the influence of neighboring spermatogenic cells as demonstrated by its reduction in hypospermatogenesis with respect to normal spermatogenesis and a further reduction in Sertoli cell-only syndrome. During testicular development in the rat (from 2 to 45 days of age) the PD1 mRNA level became detectable at 14 days and then increased steadly with an advancement of age. These findings suggest that PD1 may play a role in the regulation of spermatogenesis and may be a potential candidate gene for defects of male fertility.